An Evolved Packet System (EPS) may include a Mobility Management Entity (MME), which is responsible for control-plane mobility management. The MME manages user contexts and mobility states, and allocates temporary identities to users. A Home Subscriber Server (HSS) may include a home network server and/or a Home Location Register (HLR) for storing subscription information. A Packet Data Network (PDN) Gateway (GW) is a user-plane anchor between a 3rd Generation Partnership Project (3GPP) access system and a non-3GPP access system, and terminates the interface to external PDNs. The core network of the EPS is accessible to the User Equipment (UE) based on the 3GPP access technology, and to the UE based on non-3GPP access technologies such as Wireless Local Area Network (WLAN), Code Division Multiple Access (CDMA), and Worldwide Interoperability for Microwave Access (WiMAX). The UE based on non-3GPP access technologies is authenticated and authorized by a 3GPP Authentication, Authorization and Accounting (AAA) server. The AAA server receives a request from a non-3GPP UE, and obtains subscription data from the HSS. After the AAA server authenticates and authorizes the UE successfully, the UE is allowed to access the EPS network to use services.
In the EPS, the network allocates a PDN GW to an APN-oriented PDN connection initiated by the UE. The information about the PDN GW may be subscribed to statically or generated dynamically, and stored in the HSS. The PDN GW information provides a signaling and bearer switching anchor when the UE switches from the 3GPP access to the non-3GPP access subsequently, or vice versa. When the PDN GW information generated dynamically changes, the network element triggers the HSS to update the stored PDN GW information. The user of the HSS may subscribe to a wild card APN whose value is “*”. The wild card APN enables the user to access any network by using a given PDN type (such as IPv4, IPv6 or IPv4-IPv6). The wild card APN is expressed as “*”.
In special scenarios, for example, if the user subscribes to a wild card APN, when the UE accesses the network, the network element selects a specific APN for the user according to the APN information in the request from the UE or according to the network configuration, and allocates a specific PDN GW for the APN access to set up a PDN connection. When the network allows the UE to access multiple PDNs simultaneously (through multiple APNs) to use services, the network may select different PDN GWs according to the PDN (or APN) accessed by the UE. The APN accessed by the UE and the corresponding PDN GW information need to be stored in the HSS and used to update the corresponding information on other network elements. In the prior art, after HSS receives the relevant APN information and PDN GW information from the MME, Serving GPRS Support Node (SGSN), in which GPRS is short for General Packet Radio Service, and/or AAA server, the HSS creates an APN subscription record dynamically and updates the corresponding information on other relevant network elements synchronously according to the new APN subscription record. Meanwhile, the HSS makes a special mark to the APN subscription record to make it be different from the APN subscription record of static subscription, and the APN subscription record can be deleted conveniently after the UE is disconnected from the APN or detached from the network subsequently. After the UE is disconnected from the APN or detached from the network subsequently, the MME, SGSN and/or AAA server notifies the HSS to delete the PDN GW corresponding to the APN subscription record. The HSS deletes this APN subscription record, and deletes the APN subscription record in other network elements synchronously.
The foregoing process shows that the HSS needs to make a special mark to an APN subscription record when creating the APN subscription record so that the APN subscription record can be created and deleted between the HSS and other network elements (such as the MME, SGSN and/or AAA server) synchronously. Unnecessary interactions occur between the HSS and other network elements. For example, when the UE is disconnected from an APN, the MME and/or SGSN sends a PDN GW update message to the HSS, requesting deletion of the PDN GW information corresponding to the APN. The HSS deletes the APN subscription data according to the special mark made at the time of creating the record, and then sends a user data deletion request message to the MME/SGSN to delete the corresponding APN subscription record on the MME/SGSN, therefore adding unnecessary operations between the HSS and other network elements and reducing the data transmission performance of the network. Further, when creating the APN subscription record, the HSS needs to create not only the APN and PDN GW information, but also the information required in the ordinary APN subscription record, for example, the PDN type, and context identifier, which adds an unnecessary overhead to the HSS.